If you don't find the option to edit the WIFI credentials even after following all the steps you can try restarting modem for a minute then Please follow the steps mentioned on the below article to change the WIFI credentials on the modem interface.

http://arris.force.com/consumers/articles/General_FAQs/SVG2482AC-Changing-the-Wi-Fi-Name-and-Password

Thanks for your response !

Here the problem is that the Edit option does not let me change anything , basically all the fields are non -editable even when I click on EDIT .

I even tried doing a Factory reset but as soon as I configure network name & Password either for 2.4 or 5 GHz the other wifi disappears .

So due to this issue I am unable to make use of both the WIfi .

Please advise .

Thanks!

Since the Wi-Fi network name is disappears, could you let us know the firmware version.

Also I suggest you to factory reset the modem and try to login the GUI portal without co-axial cable and customize the Wi-Fi credentials.